Grinding machine



May 2, 1939. A. E. HAMILTON ET AL GRINDING MACHINE 10 Sheets-Sheet 1 Original Filed July 6, 1956 g INVENTOR May 2, 1939- A. E. HAMILTON ET AL 2,156,453

GRINDING MACHINE Original Filed July 6, 1936 10 Sheets-Sheet 2 5 8. @m B. 2 H 8 q Nah 2, 1939- A. E. HAMILTON ET AL 2,156,453

I GRINDING MACHINE Original Filed July 6, 1936 10 Sheets-Sheet 3 10 Sheets-Sheet 4 May 2, 1939. A. E. HAMILTON ET AL GRINDING MACHINE Original Filed July 6, 1936 May 2, 1939. A. E. HAMILTON ET AL GRINDING MACHINE Original Filed July 6, 1936 Sheets-Sheet 5 Qu. mw

nv O 8 um vw Mm GRINDING MACHINE Original Filed July 6, 1936 10 Sheets-Sheet 6 I I I I HHHHHHHHH I U INVENTO May 2, 1939. A, HAMILTON ET AL 2,156,453

GRINDLNG MACHINE Original Filed July 6, 1956 10 Sheets-Sheet 8 fig 22.

y 1939. A E. HAMILTON ET AL 2,156,453

GRINDING MACHINE Original Filed July 6, 1936 10 Sheets-Sheet 9 fig. 14. m

INVENTORS May 2, 1939.

A. E. HAMILTON ET AL GRINDING MACHINE 6 w m. 0 N i 1 w w P g 'y 1 4 4 A W 5 5 w o m r u w L J u m m 3 M m n u u a m u T m u n u 2 0 n u u M u o J u L M a Mm m n n M M n u u n v 1/ u n n 7 I fi l b. a m m m m .u 5 u ,n u n 0 1 m m u n m 0 u n I 6 m M L m a 1 L M u i s u n m F m f f n m exhaust Patented May 2, 1939 UNITED STATES GRINDING MACHINE.

Alfred E. Hamilton, Pittsburgh, and Laszlo M. Stempel, Coraopolis, Pa.

Application July 6, 1936, Serial No. 88,952 Renewed August 27, 1938 15 Claims.

This invention relates to grinding machines particularly suitable for automatically grinding the surfaces and edges of plates, blades or other blanks of elongate form to predetermined shape and contour, and is hereinafter described as employed in the grinding and shaping of knife blades.

One object of our invention is to provide a work holder of such form that blanks can be carried thereby across the face of. a grinding element and the blank maintained against shifting and deflection under grinding pressure and wherein mechanical spring of the holder is eliminated.

Another object of our invention is to provide means for regulating the rate of travel of a work holder in a direction radially of a grinding element. I

Another object of our invention is to provide a grinding machine which is automatic in operation, wherein the operations of feeding, advancing, grinding and discharging the blanks are effected sequentially and in timed relation, but wherein the time required for the grinding operation may be regulated at will and independently of the timed relation of the other operations.

A further object of our invention is to provide means for oscillating the blanks during grinding thereof for grinding the blanks along a curved line and soadjusting the oscillating means that only desired portions of the blanks will be ground on such curved line.

Still another object of our invention is to pro- 35 vide means for so varying the longitudinal position of the blanks relative to the grinding wheel during grinding thereof, that the depth of grinding and consequently the contour of the ground surface may be effected as desired.

In the accompanying drawings Figure. 1 is a plan View of the grinding apparatus; Fig. 2 is a side elevational view thereof, partially in section; Fig. 3 is a View taken on the line IIIIII of Fig. 1; Fig. 4 is a View taken on the line IVIV of Fig. 2; Fig. 5 is an enlarged View taken on the line V-V of Fig. 1; Fig. 6 is a view taken on the lineVI-VI of Fig. 5; Fig. 7 is a plan View of one of the work holders, on an enlarged scale; Fig. 8 is a view taken on line VIII-VIII of Fig. 7; Fig. 9 is a view taken on the line IXIX of Fig. 7 Fig. 10 is a view taken on the line XX of Fig. 6; Fig. 11 is an enlarged view taken on the line XXI of Fig. 4 Fig. 12 is an enlarged view taken on the line XIL-XII of Fig. 5; Fig. 13 is a view taken on the line XIII-XIII of Fig. 12; Fig. 14 is an enlarged view taken on the line XIV- HV of Fig. 1; Fig. 15 is a view taken on the line XVXV of Fig. 14; Fig. 16 is a partial plan view of. a portion of the structures of Figs. 14 and 15; Fig. 17 is a view. taken on the line XVl1-XVII of Fig. 14; Fig. 18 is an enlarged vertical sectional view of certain of the valve members of Fig. 17; Fig. 19 is a view taken on the line XIX-XIX of Fig. 18; Fig. 20 is a view taken on the line 10 XX--XX of Fig. 18; Fig. 21 is a development of the timing cams of the timer structure of Fig. 17; and Fig. 22 is a diagrammatic view showing the timing mechanism and the piping connections leading therefrom to various portions of 15 the apparatus.

The apparatus includes a base III upon which is mounted a slide II (Figs. 1, 2 and 3). A block I2 is slidably supported on the slide II for adjustment transversely of the slide I I. A shaft 20 I3 is supported upon the block I2, with suitable bearings. A grinder head I4 is secured to one end of the shaft I3 and carries a grinding wheel or ring composed 01. emery or other suitable abrasive material. The other end of the shaft 25 I3 is provided with a pulley I6 which is driven by an electric motor I'I, through a pulley I8 and suitable belt devices I9. The motor casing is mounted on the bearing block I2 so that the driving connection just referred to can be maintained properly during adjustments of the block I2 on the slide II.

The slide II is adjustable by means of screws 20 so as to vary the position of the grinding Wheel I5 relative to the Work carrier, to be hereinafter described, in directions axially of the Work carrier. The slide I2 is adjustable to move the grinding wheel toward and from the work carrier to compensate for Wear on the face of the grinding wheel. This-adjustment is effected by 40 means of a nut 2| which is carried by the slide I2 with which a screw shaft 22 has threaded engagement. The screw shaft is journalled in the slide II and carries a worn wheel 23 that meshes with a worm 24. The worm 24 is operated by a hand wheel 25 to effect the adjustment just above referred to. By reason of the Worm gear and screw connections just described, very accurate adjustments. of the grinding Wheel toward and from the face of. the work carrier can be effected, and the grinding wheel will remain in such set positions.

The work carrier is mounted upon a shaft 21 which is disposed at right angles to the grinder shaft I3 and is supported at its ends in bearings 28 and 29 respectively, that are mounted upon the base Ill. The work carrier includes end plates or spiders 3D and 3| which have hub-like portions supported by suitable bearings upon the shaft 21. The spiders 3i] and 3| are rigidly connected in unitary relation by tie rods 32 arranged in groups of three. The spiders together with the rods 32 constitute a rotatable carrier for the work holders.

Each group of rods 32 carries a work holder 33. The work holders are supported for sliding movement on the rods 32 and each comprises a casing or housing having three cylindrical bores through which the rods 32 extend (Figs. 6, 8, 9 and 11). On each housing 33 a bracket 35 is pivotally connected at 36. The bracket has ears 3! through which screws 31a extend, the screws being threaded into the bosses 38 on the housing 33. Springs 39 are interposed between the heads of the screws and the ears 3? to yieldably urge that end of the bracket 35 toward the housing 33.

The bracket has journalled thereon a roller 4|] that bears against a pattern rod or guide rod 4| which may be of such form as to control the shape to which an article may be ground, as will be hereinafter explained. The rod M extends through the housing 33 and through spiders 3! and 3|, and is detachably keyed to the spider 3| by a key 42.

The housing 33 carries a back-up roller 43 that supports the rod 4| against deflection under grinding pressures. The roller 43 is mounted on an eccentric portion of a shaft M which is carried by the housing 33, and this shaft is rotatably y adjustable in order to raise and lower the backup roller relative to the guide rod 4|, to compensate for wear and to suit rods of various diameters. The shaft is supported between split bearing members 45, which can be brought into tight clamping engagement with the shaft. Loosening of these clamps will permit rotatable adjustments of the shaft 44.

The bracket 35 carries a rod 41 upon which a recessed block 48 is mounted for rocking movements (Figs. 5, 8 and 9). Springs 49 and 5B are interposed between the block 48 and the bracket 35, near the ends thereof, in order to yieldably maintain the block in a predetermined position upon the bracket 35. The springs 56 are preferably made somewhat heavier than the springs 49, so that they will offer increased resistance to backward tilting of the block 48 when the work is being moved against the grinding wheel.

A clamp block or bar 52 is secured to the block 48. The block 52 is suitably recessed in its outer face for the reception of the knife blades or other articles to be ground. The walls of the recesses serve to prevent displacement or sliding of the work on the block 52 through friction of the grinding wheel.

The knife blade or other work, indicated by the numeral 54, is held upon its seat 52 by a clamp 55. The clamp 55 is pivoted upon the block 48 and is yieldably urged toward the clamping block 52 by springs 56. The clamp is opened and closed by means to be hereinafter described. The recessed block 48 has at one end an extension or arm 51, by means. of which the recessed block 58 and the parts carried thereby will be oscillated on the shaft 41, as will be hereinafter described.

A cylinder 58 is formed in each work holder, and extends axially thereof (Fig. 6). A piston rod 59 extends through each cylinder and into the spiders 3|] and 3|. A piston 69 is secured to the mid-portion of the piston rod 59, and fits within the cylinder 58. The cylinder is provided with a packing gland 6| at each end thereof, to prevent leakage of fluid from the ends of the cylinder.

The piston rod 59 is provided with bores extending from each end thereof to the piston 60, ports 62 being provided at the inner ends of these bores so that fluid pressure can be admitted into the cylinder at opposite sides of the piston 53. The work holder can thereby be reciprocated longitudinally of the tie rods 32.

With the parts in the positions shown in Fig. 6, the admission of fluid pressure to the right hand end of the piston will cause the work holder to move to the right, carrying with it the work clamping devices above described. The roller Ml will move along the pattern rod 4| and be held in yieldable engagement therewith by the springs 39, as above described, so that the bracket 35 will be oscillated or be gradually tilted in a radial direction relative to the axis of the carrier, and consequently vary its position relative to the grinding wheel, thus varying the depth to which the grinding of the work is effected and consequently the contour of the ground surface, which contour is determined by the shape of the pattern rod 4|. As shown more clearly in Fig, 2, there are six work holders mounted upon the rotatable carrier, and each work holder is of the construction above described.

The spider 30 of the carrier has an extended hub to which is secured a rachet wheel 63 and a locking disc 64 (Figs. 5 and 6). The locking disc has six notches in its peripheryone for each of the work holders. A locking lever 65 is pivotally mounted on the bearing housing 28 and carries a boss or lug 55, which is moved into the notches of the locking disc 64, to hold the carrier against rotation when the work holder is in grinding position.

Step-by-step movement is given to the carrier by means of -a pawl 61 which engages the ratchet teeth in the ratchet disc 53. The pawl 61 is pivotally mounted between arms 68 that have circular extensions which are journalled on the hub of the spider 30. The outer ends of the arms '68 are pivotally connected to a piston rod 69 which extends into a cylinder H3. Fluid pressure is alternately admitted to opposite ends of the cylinder 10 through pipes H and 12, to effect reciprocation of the piston rod 69, and to actuate the pawl to rotatably advance the carrier with a step-by-step movement. A spring 13 yieldably holds the pawl 51 in working engagement with the ratchet teeth. This spring 13 is carried by one of the arms 68.

Since the inner end of the piston rod 69 oscillates on an arc, provision is made to permit the cylinder to oscillate and thereby avoid binding of the piston rod 59. To this end, the cylinder l!) is pivotally connected at '55 to the bracket arms 16, which extend from the housing 28,

The locking lever 65 is operated by a piston Tl disposed within a cylinder 13. The piston H is carried by a piston rod 79 which extends toward and is opposite to the piston rod 69. The inner end of the piston rod 19 carries a roller 89 which engages the upper end of the locking lever 65 to push the lever into locking engagement with the disc 64, when fluid pressure is admitted to the cylinder 18 through a pipe 8|. Air pressure admitted to the cylinder 18 will exert a yieldable force to push the locking lever toward the disc 64, so that when a notch comes opposite to the lug 56, the lever will snap into locked position. Retractive movement of the piston T! and release of the locking dog 66 will be effected by the piston rod 69 moving toward the left (Fig. 5), so that a roller 82 on the inner end of the piston rod 69 will engage the inner face of the lever 65, thus releasing the look at 66 automatically when the pawl 61 is being drawn back to engage another notch in the ratchet wheel 63. The upper end of the lever has an extension which engages with a bell crank lever 86 which is pivotally mounted in a housing 81, that is positioned upon the cover plate of the housing 28. The horizontal leg of the bell crank lever engages the stems of valves 88 and 89 which control admission of air through the piston rods 59 to the cylinder 58, as will be hereinafter described.

Means are provided for stopping the rotative movement of the carriage at points intermediate where it is locked by the lever 65, to permit of feeding blanks to the work holders. This means is shown more clearly in Figs. 1, 5 and 6, and constitutes a piston rod 90 operating in a cylinder 9| to the opposite ends of which fluid pressure is admitted through pipes 92 and 93, to effect reciprocation of the piston rod. The outer end of the piston rod is movable into the path of the pattern rods 4 I, the timing relation of the feeding mechanism and the actuation of the locking piston 90 to be hereinafter described.

As shown more clearly in Figs. 1, 2 and 4, the feeding device for supplying the work or blanks to the work holders is mounted upon brackets I00, which extend upwardly from the base I0, and comprises a slide plate housing IOI in which a slide plate I02 is mounted. At its forward edge, the slide plate carries projecting fingers I03 which, when the slide plate advances, will engage the lowermost blank 54 of a stack contained within vertical slide or guide ways I04. Forward movement of the slide plate I02 will slide the bottommost blank between the pivoted clamping jaw 55 and the clamp block 52.

The clamp block 52 is recessed or grooved, as shown in Fig. 6, to permit the fingers to move sufficiently far that the blank will be properly pushed into the recessed upper face of the clamp block, and beneath the pivoted clamp 55. Ree ciprocatory movement of the slide plate I02 is effected by means of a piston rod I05 and a cylinder I06, fluid pressure being admitted to the opposite ends of the cylinder through pipes I01 and I08,

The operation of the feed slide is, of course, timed relative to the movements of the other parts, as will be later explained.

As shown more clearly in Fig. 2, the work holders as they approach blank receiving position, pass beneath camming blocks I09, with which the rear ends of the pivoted clamp 55 engage to open the clamp for the reception of a blank. The clamping jaws 54 are operated in a somewhat similar manner to open the same at the discharging station, after the blanks have passed the grinding wheel. This opening means is shown in Fig. 2 and consists of a camming block I I 0 that will be engaged by the tail of each clamp to rock the same and effect release of the ground blank.

As heretofore mentioned, each work holder, when in position adjacent to the grinding wheel, is moved along the rods 32 by admission of fluid pressure to its cylinder 50 through the piston rods 59. The ends of the piston rods are secured in the spiders 30 and 3|, and the bores thereof communicate with ports III, as shown more clearly in Figs. 6 and 10. In order tocontrol admission of fluid pressure and exhaust from the cylinder, we provide blowhead devices which are moved against the faces of the spiders into sealing engagement therewith, and effect registry with the ports III. These blowheads are mounted on the bearing standards 28 and 29. Similar blowheads are also carried by the bearing standards 28 and 29, in order to effect retractive movements of the work holders after they have been advanced on their guide rods, such retractive movements taking place at a point which is diametrically opposite to the grinding station. Each of these blowheads is similar in construction and comprises a cylinder II2 which is suitably secured to the bearing standards. The cylinder is provided With a stem portion II3 for supporting a piston rod II4, the piston rod extending through both ends of the cylinder. On its inner end, the piston rod carries a bushing II5 of yieldable material, such as rubber or the like. A piston II6 carried by the piston rod H4, is contained within cylinder H2, and serves to move the piston rod inwardly toward one face of the adjacent spider. This movement is effected by the admission of fluid pressure through pipe 1, a spring II8 serving to retract the piston rod when the fluid pressure is released. At its outer end, the piston rod H4 is extended through a suitable packing gland and nut I I9, and carries a valve I20. The rod II 4 is bored out longitudinally, so as to permit passage of fluid pressure therethrough, the sealing member II5 having a passageway therethrough, communicating with such bore.

When fluid pressure is admitted to the pipe II], the piston and piston rod move inwardly:

against the tension of the spring I I8, thereby moving the sealing member II5 into sealing engagement with the face of the adjacent spider and effecting a continuous passageway for fluid pressure to the piston rod 59. Such fluid pressure is admitted through a pipe I2I, through control valve I20, and the passageway through the rod I I4, the sealing member H5, and the port III. When the pressure is removed from the pipe I I1, the spring I I8 causes the piston rod of the sealing member to be moved away from the face of the spider, thereby permitting successive indexing .movement thereof.

It will be seen that one of the blowheads is moved into engagement with its associated spider to permit admittance of fluid pressure to the cylinder 58, while the blowhead at the opposite end of the same piston rod, associated with the cylinder 58, moves into engagement with its associated spider, to control exhaust from the cylinder 58. By means of adjustment of the valve I20, the speed of movement of the work holder is regulated by controlling the rate of exhaust from the cylinder 58. Therefore, the time to which a blank is subjected to a grinding operation is controllable as desired,

During movement of the work holder to move a blank radially of a grinding element, we provide means for causing the clamp block 52 and the blank carried thereby, to be oscillated relative to the face of the grinding element. This mechanism, as shown more clearly in Figs. 1, 5, 11, 12 and 13, comprises a rock shaft I 25 which is journalled at one end in the upright I00 and adjacent to its other end in an upright I26. A crank I21 is secured to one end of the rock shaft I25, and V shaft I25 is provided with a radially extended portion I33, to which is secured at its upper and lower sides, plates I34 and I35, forming thereby an extended slotted member. The heretofore mentioned lever 51 secured to the end of the work holder block 48 is moved into position ad- J'acent to one end of the slotted oscillating memher, when the work holder is moved into grinding position. During traveling movement of the work holder on the rods 32, the end of the lever 51 moves into position between the plates I34 and I35, such plates being flared at their forward ends to facilitate entrance of the lever therebetween, while the shaft I25 is being oscillated. Thus rocking movement throughout a predetermined portion of traveling movement of the work holders on the rods 32 is imparted to the work holder.

The degree of oscillation or the extent of rocking movement imparted to the work holder is controlled by adjustment of the point of connection of the connecting rod I28 with the crank arm I21. The crank arm I21 slidably carries a block I36, as shown more clearly in Figs. and 12, which is movable longitudinally of the crank arm, to various positions therealong. The block I36 is provided with a trunnion I31, to which the upper end of the connecting rod I28 is connected. The block I36 has threaded connection with a screw rod I30 which is suitably journalled in end plates carried by the crank arm. Through rotation of the screw rod I38, the crank throw may be readily adjusted to obtain the desired degree of oscillatory movement of the work holders, through the heretofore-described connection.

Near the end of the movement of the work holders on the rods 32, the lever 51 moves out of engagement with the plates I34 and I35, the grinding operation on a blank carried thereby, being then completed. A push rod I40 is slidably mounted in the bracket I26 in position to be engaged by the lever 51 after it has moved out of engagement with the oscillating device. The push rod I40 engages one end of a bell crank lever M! which is pivotally mounted at I42 on the bracket I26, the other leg I43 of the bell crank lever having secured thereto a cable I44, the cable being moved through movement of the bell crank lever I4I for a purpose to be hereinafter described. The bell crank lever is normally maintained in a central position with the push rod in projected position, by means of springs I45.

We have found it desirable to utilize fluid pressure to actuate the various moving parts of the machine, and in order to effect operation thereof in proper sequence, we provide timing mechanism for controlling the admission and exhaust of fluid pressure to the motivating devices heretofore described. The timer, as shown more clearly in Figs. 14, 15 and 16, comprises a casing I50, in which is disposed a shaft I5I mounted in suitable bearings in an end plate I52 and an end housing I53. A series of cams I54 are mounted on the shaft I5 I. Each cam engages the stem of a valve I55, which is carried in a valve housing I56.

As shown more clearly in Figs. 18, 19 and 20, each valve body is provided with a pair of valves I55. One of the valves controls the flow of fluid pressure from an inlet port I51 to an outlet port I58, formed in the valve body. The other valve I55 controls exhaust of fluid pressure from the port I58'to an exhaust port I59. The valves I55 are of the poppet type and are normally held on their seats by means of springs I60.

The timer is driven from the sprocket wheel I6I which is mounted on the shaft I30 of the speed reducer I32. A driving chain I62 passes around the sprocket "SI and around a sprocket wheel I63 that is mounted on one end of a shaft I64, the shaft I64 being journalled in the end plate I52 and the end housing I53. On its inner end, the shaft I64 carries a pinion I65 meshing with a gear Wheel I66, which is suitably secured to the hub I61 of a clutch element I68, the clutch I68 being supported by bearings I69 in the housing I56. The face of the clutch element I68 is provided with notches or recesses for the entry of a clutch dog I10, which is carried by a wheel element I1I, that is secured to the shaft I5I. The clutch dog I is slidably mounted in the wheel element I'II for movement in directions axially of the wheel element into a notch in the clutch element I68. The clutch dog is yieldably urged in clutch engaging position by means of springs I12. The clutch wheel I1I is provided with an annular groove or channel I13 and the forward end of a lever I14 rides within this groove. The other end of the lever I14 is pivotally mounted at I to the housing I50.

Spring I16 serves to yieldably urge the lever I14 toward the axis of the wheel Ill. The forward end of the lever I14 is provided with a cam nose portion I11, which lies. in the path of and cooperates with an inclined surface I18 (Fig. 16),

of a slot in the upper side of the clutch dog I10,

to cause withdrawal or retraction of the clutch dog from a notch in the clutch element I60 at the completion of each revolution of the shaft I5I and the clutch wheel Hi.

It will thus be seen that when the clutch dog I10 is released by lifting movement of the lever I14, it moves into engagement with one of the notches in the disc I68, and thereby completes the driving connection between the clutch element I68 and the clutch wheel HI, and thereby drives the cam shaft I5I. As the cam shaft and the clutch wheel I1I approach the end of a single revolution thereof, the cooperating camming surfaces I11 and I18 cause withdrawal of the clutch dog I10, thereby breaking the driving connection for the cam shaft.

As heretofore described, the bell crank lever I4I is actuated when the work holder reaches the end of its movement on the rods 32 and the notches of the clutch element I68, thereby initiating another cycle of operations. A stop screw I8I limits upward movement of the lever I14 and prevents its movement out of the annular groove I13. During each complete revolution of the cam shaft, the cams I54 carried thereby cause actuation of the valves I55 in predetermined sequence, and thereby time the operation of the grinding machine, the sequence of operation and the timing periods for the various cams being graphically illustrated in Fig. 21.

Referring now to Figs. 21 and 22, fluid pressure from a suitable source, not shown, is admitted past a valve 200 and is directed through pipes 201 to the inlet port I51 of each of the valve bodies I56, associated with the timer mechanism. With the parts in the position as shown in Fig. 2, and with the motor I3! in operation, the carriage control lever I14 may be manually tripped to cause the clutch dog I10 to move into driving engagement with the clutch element I68, thereby causing the cam shaft I 5I to be operated. As shown in Fig. 21, the cams which control admission of fluid pressure from the pressure line 20I to the various cylinders, are shown in full lines, while the cams that control the exhaust from the said cylinders are shown in dotted lines. The cam I54a actuates itsvalve I55, thereby permitting fluid pressure flow past the valve from the inlet I51 to the outlet I58. The outlet I58 is connected with the pipe 12 leading from the indexing cylinder I0. 1

The cam I54b permits closure of its associated valve I55 to prevent exhaust of fluid pressure through the exhaust port I59. The fluid pressure admitted to the cylinder I0 causes the piston contained therein to move to the left, thereby moving the indexing mechanism into its dotted line position, as shown in Fig. 5. It will be seen that the roller 82 on the forward end of the piston rod 69 during retractive movement of the piston, enages the locking lever 65 and moves it into its dotted line position, thereby withdrawing the locking dog 66 out of a notch in the notched plate 64, thus releasing the carriage.

Movement of the lever 65 out of locking position results in disengagement thereof with the crank lever 86, thereby permitting the valves 88 and 89 to close. Fluid pressure is admitted to the valves 88 and 89 through a pipe 203. The valve 88 controls flow cf fluid pressure to the blowhead cylinders I I2, so that when this valve is open, the pressure is admitted to the cylinders to cause I the piston rods II4 thereof to move the discs I I5 into sealing engagement with the adjacent spider members 30 and 3|, and establish a closed conduit to the cylinder 58. The valve 89 controls flow of fluid pressure through pipes 204 connecting with certain of the pipes I2I of the blowheads.

With lever 65 in its retracted or release position, it engages the stem of a valve 205 which is mounted in a valve body 206 and suitably secured to the housing 28. The valve 205 serves. to control exhaust of fluid pressure from the blowhead cylinders H2, thepipes or conduits I I1 thereof being connected to a port in the valve body 206, located at one side of ,the valve 205. At the opposite side of the valve 205, the valve body is provided with an exhaust port 208. It will be seen, therefore, that with the valve 205 open, the residual pressure in the cylinders I I2 is exhausted to the atmosphere, thereby permitting the springs II8 to move the sealing discs II5 away from the spiders. Following these operations, cam I540 actuates its valve I55 and admits fluid pressure to the pipe II leading to the opposite side of indexing cylinder I0. The piston therein is actuated, the pawl 61 engaging a tooth of the ratchet wheel 63, and causing advancing movement of the carriage, The carriage is thereby moved from its position shown in Fig. 2 toward the blank feeding position. However, before the carriage reaches the feeding position, the cam l54d opens its valve I55 and admits fluid pressure to a pipe 2I0 lead ing to the pipe 93 of the locking cylinder 9|.

The pipe 2I0 also has connection with the pipe I07 of the feeding cylinder I06. The piston rod is thereby moved into position to be engaged by the projecting end of a rod II to stop the carriage in its blank receiving position, as hereto fore described. The pressure admitted to the cylinder I06 causes movement of the slide plate I 02, thereby feeding the lowermost blank 54 from the magazine into position on the clamp bar or block 52. During the feeding movement of the blank to the holder, the cam I540 permits its valve I55 to close, thereby preventing flow o fluid pressure to the indexing cylinder.

Upon completion of the blankfeeding operation, the cam I54Z permits closure of its valve I55, thereby preventing pressure flow to the feeding'cylinder I06. Its associated cam I54e operates to open the exhaust port I59, thereby permitting the retraction of the piston in. the feeder cylinder and exhaust of air therefrom.

To effect retraction of the blank feeder and retraction of the locking rod 90 to unlock the carriage, cam I 54} operates its valve to admit fluid pressure to its outlet I58, which in turn is connected to the pipes I08 and 92. Substantially simultaneously with admission of this fluid pressure to cause unlocking of the carriage and retraction of the blank feeder, fluid pressure is again applied to the indexing cylinder I0 by the cam I540, the indexing mechanism being actuated to complete the indexing of the carriage.

As shown in Fig. 2, as soon as the carriage moves slightly away from. its intermediate loading position, the trailing end of the clamp 55 disengages from the cam block I09 and thereby securely clamps the blank on the Work holder. The blank feeding fingers will, of course, move away from the Work holders quite. rapidly, so

that there is no danger of their being damaged through movement of the carriage.

Prior to the completion of the carriage indexing movement, valve I54g admits flow of fluid pressure to the pipe BI leading to the cylinder I8.

The piston II therein is moved to cause the piston rod I9 to engage the upper end of the locking lever 65 and yieldably urge the locking dog 66 into engagement with the face of the locking disc 64.

When the next notch in the locking disc 64 is brought into position adjacent the locking member 66, it will drop quickly into such notch and lock the carriage. This snap action of the locking member eliminates danger of over-running of the carriage past the grinding position.

Shortly thereafter, cam I54c permits closure of its valve to remove pressure from the indexing cylinder, while its associated exhaust-controlling cam operates to exhaust pressure from the indexing cylinder to the atmosphere.

When the locking lever moves into locking position, it actuates the crank lever 86, thereby actu' ating the valves 88 and 89. The valve 88 is actuated slightly in advance of the Valve 89, the connections heretofore described, the air pressure is admitted past the valve 88 to the blowhead cylinders H2, and air pressure is admitted past valve 89 to the bores in piston rods II4. Flow of fluid pressure is therefore effected through the ports I II and through the piston rods 59, to one side of the piston 60 in the cylinder 58. tion is thereby moved along its guide rods 32. the opposite side of the carriage, the previouslymoved work holder will be moved alongits guide rods and returned to its normal position.

Pressure is applied to the blowhead cylinders' and flows through such blowheads to actuate the work holders, so long as the locking lever 65 is maintained in its locked position. As'the timer approaches the end of its cycle of movement, cam

I54a actuates its valve to admit fluid pressure through the pipe I2, and thereby causes the in-' dexing piston to move in a retracting direction.

However, before the indexing mechanism is fully retracted, the air pressure is removed' through' Through The work holder which is in grinding posi closure of the valve associated with the cam I54a, so that at this time the locking lever is not moved out of carriage-locking position. The indexing mechanism is merely so positioned that upon completion of the grinding operation it may be fully retracted to cause quick actuation of the locking lever and consequent closure of the valves 88 and 89-, to remove pressure from the blowheads and the work holder actuating pistons.

After partial retraction of the indexing mechanism, as above described, the camming surface I18 of the clutch dog I'Ifl engages the cam surface of the lever I11, and the clutch dog is caused to move out of driving engagement with the clutch element I68.

At this time the timing mechanism is thereby declutched from its driving mechanism, after making one complete revolution, and is not reactuated until the work holder moves along the guide rods 32, and actuates the trip lever MI through engagement with the push rod I46. When the trip lever is actuated, the cable I44 lifts the lever I14, thereby releasing the clutch dog I10 and causing succeeding cycles of operations.

The speed at which the work holder is moved along the guide rods 32, is controlled by controlling the exhaust of air from the one side of the cylinder 59. This control of the exhaust flow is efiected by means of the valve I20 on the outer end of the piston rod I I4. By adjustment of the valve I20, the rate of travel of the work holder may be regulated as desired. This is an important feature of our invention since for certain types of articles or blanks, it may be desirable to subject the blanks to a longer or shorter grinding period. For example, with relatively thick blanks where a large amount of stock is to be removed, it is desirable to provide a greater time for removing such stock to prevent burning of the metal and rapid wear on the grinding element, than when only a small amount of stock isto be removed from a blank.

Another important feature of our invention resides in the provision of oscillating the blanks during grinding operation thereon, in order to form blanks with convex sides. Also, as shown in Figs. 12 and 13, not only may the degree or amplitude of oscillation imparted to the blank holder be adjusted through shifting of the point of connection of the connecting rod I28 with the crank arm I21, but the angle of oscillation relative to the face of the grinding wheel may be adjusted through lengthening or shortening of the connecting rod I28, which may readily be effected by means of the adjusting nut 2I5. For example, when the connecting rod I 28 is shortened so that the line a (Fig. 13) indicates the center of oscillatory movement, the work holder and the blank carried thereby will be moved and oscillated in an angular position relative to the face of the grinding wheel. This results in forming only the lower portion of the blank with a convex surface, whereby greater strength may be retained in the blank by non-removal of a too great amount of material when sharpening the lower edge of the blank.

In some instances, when it is desired to grin the blank with flat sides, We hold the oscillating mechanism against oscillation so as to maintain the face of the blank at any predetermined angular position relative to the grinding wheel. This is effected by merely removing the lower end of the connecting rod I28 from the eccentric I29 and positioning it on a stud 2I6 secured to the bracket I26.

It will be seen that in the operation of the apparatus, the timing device is intermittently set in motion to effect a cycle of operations. Thus, when the timer has reached a position at which a knife holder with its knife is to be moved across the face of the grinding wheel, the timer comes to a stop and the rotatable carrier also is locked. in a stationary position by the locking lever 65. At the completion of the travel of a knife holder across the grinding wheel, it will engage the push rod I 40 to operate the bell crank lever II and thereby again set the timer in operation to release the carrier and cause movement thereof to work-receiving position as indicated in Fig. 2, the carrier being held at that position by a stop 90. Continued movement of the timer causes a blank to be fed to the holder, the stop to be released and the carrier movement continued to bring another holder into grinding position, at which position the carrier is again locked by the latch bar 65. During movement of each holder in carrying a blank across the grinding wheel, the previously-advanced holder from which a ground blank has been discharged is retracted axially of the carrier so as to be in position to receive another blank when it reaches the charging station. Each time that a blank holder has completed its travel across the face of the grinding wheel, the timer is thereby set in motion for another cycle of operations.

We claim as our invention:

1. A grinding apparatus comprising a rotatable grinding wheel, work holders, a carrier movably supporting said holders and rotatable to bring the work holders successively into operative position with respect to the grinding wheel, means for rotating the carrier intermittently, means operative in predetermined relation to movement of the carrier for shifting each work holder longitudinally of the carrier while such holder is in grinding position and while the carrier is stationary, and means operated by said movement of the work holder for controlling said intermittent movement of the carrier.

2. A grinding apparatus comprising a rotatable grinding wheel, work holders, a carrier movably supporting said holders and rotatable to bring the Work holders successively into operative position with respect to the grinding wheel, means for rotating the carrier intermittently, means operative in predetermined relation to movement of the carrier for shifting each work holder longitudinally of the carrier while such holder is in grinding position and while the carrier is stationary, means operated by said movement of the work holder for controlling said intermittent movement of the carrier, and means for varying the rate of said longitudinal movement of the work holder.

3. A grinding apparatus comprising a rotatable grinding wheel, work holders, a carrier movably supporting said holdersand rotatable to bring the work holders successively into operative position with respect to the grinding wheel, means for rotating the carrier intermittently, means operative in predetermined relation to movement of the carrier for shifting each work holder longitudinally of the carrier while such holder is in grinding position, means for oscillating the work holder during said movement thereof, and means operated by said movement of the work holder for controlling said intermittent movement of the carrier.

4. A grinding apparatus comprising a rotatable grinding wheel, work holders, a carrier movably supporting said holders and rotatable to bring the work holders successively into operative position with respect to the grinding wheel, means for rotating the carrier intermittently, means operative in predetermined relation to movement of the carrier for shifting each work holder longitudinally of the carrier while such holder is in grinding position, means for supporting the work holder for pivotal movement on the carrier during said longitudinal travel thereof, and means mounted independently of the carrier for oscillating the work holder about its pivot during said longitudinal movement.

5. A grinding apparatus comprising a rotatable grinding wheel, a carrier, means for intermittently rotating the carrier, a plurality of work holders disposed circumferentially of the carrier and movable axially thereon across the face of the grinding wheel while the carrier is stationary, a timing device controlling the operation of the carrier-moving means and the work holder-moving means, and means actuated by movement of the work holder for controlling the operation of the timing device.

6.- A grinding apparatus comprising a rotatable grinding wheel, a carrier, means for intermittently rotating the carrier, a pluralityi of work holders disposed circumferentially of the carrier and movable axially thereon across the face of the grinding wheel while the carrier is stationary, a timing device controlling the operation of the carrier-moving means and the work holder-moving means. means actuated by movement of the work holder for controlling the operation of the timer, and means for varying the rate of movement of the work holder.

7. A grinding apparatus comprising a rotatable grinding wheel, a carrier, means for imparting rotative movements to the carrier, work holders disposed circumferentially of the carrier, fluid pressure means for moving the work holders relative to and axially of the carrier and across the face of the grinding wheel, a locking device for holding the carrier against rotation during grinding operations, means operable in timed relation to the carrier-moving means for actuating said locking device. and means actuated by locking movement of the locking device, for admitting fluid pressure to the said fluid pressure actuating means for the work holder.

8. A grinding apparatus comprising a rotatable grinding wheel, a carrier, means for imparting rotative movements to the carrier, work holders disposed circumferentially of the carrier, fluid pressure means for moving the work holders relative to and axially of the carrier and across the face of the grinding wheel, a locking device for holding the carrier against rotation during grinding operations, means operable in timed relation to the carrier-moving means for actuating said locking device, means actuated by locking movement of the locking device for admitting fluid pressure to the said fluid pressure actuating means for the Work holder, and means controlled by said movement of the work holder. for effecting release of the locking deviceand rotative movement of the carrier.

9. A grinding apparatus comprising a rotatable grinding wheel, a rotatable carrier, 2. plurality of work holders disposed circumferentially of the carrier, piston and cylinder devices on the carrier for reciprocating work holders; axially of the carrier, and provided with ports at each end of the carrier, a blowhead at one end of the carrier positioned to register with the adjacent port of each piston and cylinder device when the associated work holder reaches grinding position, a blowhead device at the other end of the carrier positioned to register with the adjacent ends of the ports successively as. the work holders pass from grinding position, a locking lever for holding thecarrier in position during each grinding movement of the work holders, means for moving the lever into and out of locking position, means actuated by the lever when moved to locking position for moving the blowheads in to cooperative relation with said ports, and other means controlled by locking movement of said lever for admitting fluid pressure through said blowheads to the said piston and cylinder devices.

10. The combination with a rotatable grinding wheel, of a work holder mounted for oscillatory movement, means for moving the work holder across the face of the grinding wheel, a rocking member mounted on an axis stationary relative to the work holder and having connection with said work holder during said movement, a device connected to said member, for rocking the member, to oscillate the work holder, and means for shifting the point of connection between the said device and the rocking member, relative to the axis of the rocking member and relative to said members connection with the work holder.

11. The combination with a rotatable grinding wheel, of a work holder mounted for oscillatory movement, means for moving the work holder across the face of the grinding wheel, a rocking member mounted on an axis stationary relative to the work holder and having connection with said Work holder during said movement, and an eccentric device connected to said member, for rocking the member, to oscillate the work holder, the connection between the said rocking member and the eccentric device being adjustable in length, to change the angular path of movement of the work holder.

12. The combination with a rotatable grinding wheel, of a work holder mounted for oscillatory movement, means for moving the Work holder across the face of the grinding wheel, a rocking member mounted on an axis stationary relative to the work holder and having connection with said work holder during said movement, a device connected to said member, for rocking the member and the work holder, means for shifting the point of connection between the device and the rocking member relative to the axis of the rocking member, and means for changing the angular path of movement of the work holder.

13. The combination with a rotatable grinding wheel, of a work holder mounted for oscillatory movement, means for moving the work holder across the face of the grinding wheel, a rocking member mounted on an axis stationary relative to the work holder and having connection with said Work holder during said movement, a device connected to said member, for rocking the member, to oscillate the work holder, and means for shifting the point of connection between said device and the rocking member, relative to the axis of the rocking member.

14. The combination with a rotatable grinding wheel, of a work holder mounted for oscillatory movement, means for moving the work holder across the face of the grinding wheel, a rocking member mounted on an axis stationary relative to the work holder and having connection with said work holder during said movement, a device connected to said member, for rocking the memher, to oscillate the work holder, and means. for shifting the point of connection between said device and the rocking member, in a direction parallel to the face of the grinding wheel.

15. The combination with a rotatable grinding wheel, of a Work holder mounted for oscillatory movement, means for moving the work holder across the face of the grinding wheel, a rocking member mounted on an axis stationary relative to the work holder and having connection with said work holder during said movement, a device connected to said member, for rocking the member, to oscillate the work holder, means for shifting the point of connection between said device and the rocking member, relative to the axis of the rocking member, and means for oscillating the work holder about an axis perpendicular to the-axis of its first-named oscillatory movement.

ALFRED HAMILTON.

LASZLO M. S'IEMPEL. 

